JP2014070701A - Bearing device, manufacturing method of bearing device, and information recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device that can be downsized, can restrain a relative inclination of a pair of rolling bearings from occurring, and can be installed accurately by restraining an inclination, a manufacturing method of the bearing device, and an information recording and reproducing device having the bearing device.SOLUTION: A bearing device comprises: a shaft 20; a pair of rolling bearings 30 and 40 fitted onto the shaft 20 and arranged side by side in the axial direction of the shaft 20. The pair of rolling bearings 30 and 40 have inner rings 36 and 46 fixed to the shaft 20, respectively. In the pair of rolling bearings 30 and 40, one side end surface 36a of the inner ring 36 of the first rolling bearing 30 arranged on one side in the axial direction is flush with one side end surface 24a of the shaft 20 or protrudes on one side from the one side end surface 24a of the shaft 20.

Description

  The present invention relates to a bearing device, a method for manufacturing the bearing device, and an information recording / reproducing apparatus.

  2. Description of the Related Art Conventionally, an information recording / reproducing apparatus such as a hard disk for recording and reproducing various kinds of information on a disk (corresponding to a “magnetic recording medium” in claims) is known. In general, an information recording / reproducing apparatus includes a head gimbal assembly having a slider for recording / reproducing signals on / from a disk, and an arm (corresponding to a “rotating member” in the claims) on which a head gimbal assembly is mounted on the tip side. It has. This arm is rotatable by a bearing device provided on the base end side. By rotating the arm, the slider can be moved to a predetermined position on the disk to record and reproduce signals.

For example, the bearing device described in Patent Document 1 is for a swing arm in which a preload is applied to a pair of rolling bearings by applying an axial load in a direction approaching the inner rings constituting the pair of rolling bearings. A bearing device comprising a flange-shaped flange formed on a part of the outer peripheral surface of an inner member (corresponding to “shaft” in the claims), and a base ( "Corresponding to the bottom of the housing").
An inner ring constituting one of the pair of rolling bearings is abutted against the flange-shaped flange. A load in a direction approaching each other (axial direction) is applied to the inner rings constituting the pair of rolling bearings. Thus, a preload is applied to the pair of rolling bearings.

  According to Patent Document 1, since the accuracy of the shape and dimensions of the outer peripheral surface of the fitting portion can be increased, even when the side surface of the collar portion formed on the inner member is abutted against the base portion, the shape and dimension of the side surface of the collar portion Since the accuracy of mounting the inner member is not greatly affected by the accuracy, it is said that the mounting accuracy of the support portion of the arm can be increased at low cost.

Japanese Patent Laying-Open No. 2005-257028

However, the conventional bearing device has the following problems.
In the conventional bearing device, since the flange portion exists between the inner ring of the rolling bearing and the bottom portion of the housing, the length of the bearing device is increased by the thickness of the flange portion. Therefore, the bearing device may be increased in size.

  In addition, the preload is applied by applying a load to the inner ring of the other rolling bearing while the inner ring of one of the rolling bearings is abutted against the other side of the collar while the one side of the collar is abutted against the jig. Is done. As described above, the reference surface (the other side surface of the flange portion) on which the inner ring of one of the rolling bearings is positioned is different from the reference surface (the one side surface of the flange portion) where the load direction of the preload is defined. For this reason, there exists a possibility that the axis line of a pair of rolling bearing may be fixed in the state which mutually inclined with respect to the axis line of a shaft by the shape variation of a collar part. As a result, a relative deviation (hereinafter referred to as “relative tilt”) occurs between the axis of one rolling bearing and the axis of the other rolling bearing, and the rotating member fitted around the pair of rolling bearings rotates. Torque ripple may occur when moving. Therefore, when information is recorded and reproduced between the slider and the magnetic recording medium, there is a possibility that recording failure and reproduction failure may occur.

  Furthermore, the conventional bearing device is supported by the housing in a state in which the flange portion is abutted against the bottom portion of the housing. For this reason, the central axis of the bearing device may be supported in a state of being inclined with respect to the vertical direction (that is, the vertical direction) of the bottom portion of the housing due to variation in the shape of the flange portion. As a result, the arm and the slider mounted on the bearing device are also tilted from the ideal position, and thus recording failure and reproduction failure may occur when information is recorded and reproduced between the slider and the magnetic recording medium. . In the prior art, the fitting part is fitted to the bottom part of the housing to suppress the inclination of the bearing device. However, as long as the collar part is in contact with the bottom part of the housing, the shape of the collar part The occurrence of tilting of the bearing device due to variation cannot be fundamentally solved.

  Therefore, the present invention includes a bearing device that can be miniaturized, can suppress the occurrence of relative inclination of a pair of rolling bearings, and can be mounted with high accuracy while suppressing inclination, and a method of manufacturing the bearing device and the bearing device. An object is to provide an information recording / reproducing apparatus.

  In order to solve the above problems, a bearing device of the present invention includes a shaft, and a pair of rolling bearings that are extrapolated to the shaft and arranged side by side in the axial direction of the shaft, and the pair of rolling bearings Each of which includes an inner ring fixed to the shaft, and of the pair of rolling bearings, one end surface of the inner ring of the first rolling bearing disposed on one side in the axial direction is one end surface of the shaft. It protrudes in the said one side rather than the one side end surface from the one side or the said shaft.

According to the present invention, the one end surface of the inner ring of the first rolling bearing is flush with the one end surface of the shaft, or protrudes to one side from the one end surface of the shaft. When attached to a mounted body such as a housing of a playback apparatus, the one end surface of the inner ring of the first rolling bearing can be mounted in contact with the mounted body. As a result, the axial length of the bearing device can be shortened by the thickness of the flange portion, compared to the case where the flange portion is brought into contact with a mounted body such as a housing as in the prior art. (Thinning in the axial direction) can be achieved.
Further, in the present invention, the pair of rolling bearings is fixed by being inserted and fixed to the shaft without abutting against the flange portion, respectively, so that the relative relationship between the pair of rolling bearings due to the variation in shape of the flange portion in the prior art is achieved. The occurrence of tilt can be suppressed.
Furthermore, when applying preload, it can be done by abutting one end face of the inner ring of the first rolling bearing against the jig, so the load direction of preload is defined using the one end face of the inner ring of the first rolling bearing as the reference plane. it can. That is, since the one end face of the inner ring of the first rolling bearing and the reference surface that defines the load direction of the preload are the same, even when preload is applied, a pair of shapes caused by the variation in the shape of the flange portion in the prior art Occurrence of the relative inclination of the rolling bearing can be suppressed.
In addition, when attaching the bearing device to the mounted body, one end face of the inner ring of the first rolling bearing can be mounted in contact with the mounted body, resulting in variations in the shape of the flange as in the prior art. And the inclination with respect to the to-be-attached body of a bearing apparatus does not generate | occur | produce. In particular, since the rolling bearing is generally formed with high accuracy, the bearing device is attached to the mounted body by suppressing the inclination of the bearing device by bringing one end face of the inner ring of the first rolling bearing into contact with the mounted body. Can be attached with high accuracy.

  Further, the shaft includes a flange portion that protrudes radially outward of the shaft between the pair of rolling bearings, and the other end surface of the inner ring of the first rolling bearing is in contact with the flange portion. It is characterized by being.

According to the present invention, when the other end surface of the inner ring of the first rolling bearing is brought into contact with the flange portion, the first rolling bearing can be easily positioned with respect to the shaft when the bearing device is manufactured.
In addition, when the bearing device is mounted with the one end face of the inner ring of the first rolling bearing in contact with the mounted body, the first rolling bearing is sandwiched between the mounted body and the flange. Thereby, when fixing a bearing apparatus to a to-be-attached body, for example with a volt | bolt, since axial force can fully be provided, a bearing apparatus can be firmly fixed with respect to a to-be-attached body.

  In addition, a cylindrical spacer is provided between the pair of rolling bearings, and the axial thickness of the flange portion is formed to be thinner than the axial thickness of the spacer. It is said.

  According to the present invention, between the pair of rolling bearings, the flange portion protruding outward in the radial direction of the shaft is formed thinner than the thickness of the spacer disposed between the pair of rolling bearings. Does not affect the overall length of Therefore, the bearing device can be prevented from being enlarged due to the formation of the flange portion, and the bearing device can be reduced in size (thinned in the axial direction).

  Further, the shaft includes a flange portion that projects outward in the radial direction of the shaft at one end portion of the shaft, and the one end surface of the inner ring of the first rolling bearing has a position corresponding to the flange portion. In addition, a concave portion into which the flange portion can be fitted is formed.

According to the present invention, since the concave portion in which the flange portion can be fitted is formed at the position corresponding to the flange portion on the one side end surface of the inner ring of the first rolling bearing, the flange portion is fitted in the concave portion. Thus, the bearing device can be prevented from being enlarged due to the flange portion, and the bearing device can be reduced in size (thinned in the axial direction).
In addition, by fitting the flange portion into the recess of the inner ring of the first rolling bearing, the first rolling bearing can be easily positioned with respect to the shaft when the bearing device is manufactured.

  Further, the outer diameter of the shaft is characterized by being uniformly formed over the entire axial direction.

  According to the present invention, since the shaft can be easily formed, the bearing device can be reduced in size, and the relative inclination of the pair of rolling bearings can be suppressed, and the bearing device that can be mounted with high accuracy by suppressing the inclination can be formed at low cost. it can.

  Further, the other side end surface of the inner ring of the second rolling bearing disposed on the other side in the axial direction is flush with the other side end surface of the shaft, or protrudes to the other side than the other side end surface of the shaft. It is characterized by being.

  According to the present invention, the other end surface of the inner ring of the second rolling bearing is flush with the other end surface of the shaft or protrudes to the other side of the other end surface of the shaft. When attached to a mounted body such as a housing of a playback apparatus, the other end surface of the inner ring of the second rolling bearing can be supported by contacting a cover member that covers the mounted body. Therefore, it is possible to attach the bearing device to the mounted body with high accuracy while suppressing the inclination of the bearing device.

  Moreover, the manufacturing method of the bearing device of the present invention includes a preload adding step of applying a preload along the axial direction to the pair of rolling bearings, and in the preload adding step, the one side of the shaft is provided. A preloading jig arranging step of arranging a preloading jig capable of abutting against one end face of the inner ring of the first rolling bearing, and contacting one end face of the inner ring of the first rolling bearing with the preloading jig. On the other hand, a pressing step of relatively pressing the inner rings of the pair of rolling bearings along the axial direction is provided.

  According to the present invention, the one end surface of the inner ring of the first rolling bearing is flush with the one end surface of the shaft, or protrudes to one side from the one end surface of the shaft. The inner rings of the pair of rolling bearings can be relatively pressed while the one end surface of the inner ring of the rolling bearing is in contact with each other. Therefore, since a preload can be reliably applied to the pair of rolling bearings, it is possible to manufacture a high-performance bearing device that can reduce vibration during rotation and suppress torque ripple.

  Further, an adhesive application step of applying an adhesive for fixing the inner rings of the pair of rolling bearings to the outer peripheral surface of the shaft is provided, and in the adhesive application step, the flange portion on the outer peripheral surface of the shaft The adhesive is applied to the region on the other side of the collar while the adhesive is applied to the region on the one side.

In general, an anaerobic adhesive is used for fixing the shaft and the inner ring of the rolling bearing. In the prior art, after simultaneously applying an adhesive to a region where one rolling bearing is fixed and a region where the other rolling bearing is fixed on the outer peripheral surface of the shaft, when one rolling bearing is inserted into the shaft, the other The adhesive may be dragged when passing through the region where the rolling bearing is fixed, and may adhere to the region between the pair of rolling bearings on the outer peripheral surface of the shaft. Thereby, there exists a possibility that an adhesive agent cannot be hardened | cured in the area | region between a pair of rolling bearings among the outer peripheral surfaces of a shaft. Further, when the bearing device is incorporated into an information recording / reproducing apparatus, for example, with the adhesive remaining uncured, outgas is generated from the adhesive and adheres to the surface of the slider, and information is transferred between the slider and the magnetic recording medium. When performing recording and reproduction, there is a risk that recording failure and reproduction failure may occur. Therefore, conventionally, after applying an adhesive to one side of the outer peripheral surface of the shaft and fixing the rolling bearing on one side, the adhesive is applied to the other side of the outer peripheral surface of the shaft and then rolling the other side. Was fixed. That is, the adhesive application process is divided into two processes.
On the other hand, according to the present invention, since the flange portion is provided between the pair of rolling bearings, it is possible to insert the rolling bearings from both the one side and the other side of the shaft. As a result, when one of the rolling bearings is inserted into the shaft, the adhesive does not pass through the region where the other rolling bearing is fixed, so that the adhesive adheres to the region between the pair of rolling bearings on the outer peripheral surface of the shaft. Can be prevented. Therefore, since the adhesive application step can be performed in one step, the manufacturing time of the bearing device can be shortened and the productivity of the bearing device can be improved.

  The information recording / reproducing apparatus according to the present invention includes the above-described bearing device, a housing that supports one end portion of the bearing device, and the pair of rolling bearings, and rotates about the axis of the shaft. And a slider mounted on the rotating member for recording and reproducing information with a magnetic recording medium. The bearing device includes a bottom portion of the housing and the first rolling bearing. The inner ring is supported by the housing in a state in which it is in contact with one end face of the inner ring.

  According to the present invention, since the bottom portion of the housing and the one end surface of the inner ring of the first rolling bearing are in contact with each other, the bearing is caused by the variation in the shape of the flange portion as in the prior art. There is no tilt with respect to the housing of the device. In particular, since the rolling bearing is generally formed with high precision, the inclination of the bearing device is suppressed by bringing one end face of the inner ring of the first rolling bearing into contact with the bottom portion of the housing, and the bearing device is accurately attached to the housing. Can be installed well. Therefore, it is possible to obtain a high-performance information recording / reproducing apparatus that is compact and can record and reproduce information satisfactorily.

  A cover member for covering the opening of the housing and supporting the other end portion of the bearing device; wherein the bearing device is in contact with the cover member and the other end surface of the shaft; It is characterized by being supported by a cover member.

  According to the present invention, since the bearing device can be supported from both the one side and the other side of the bearing device, the inclination of the bearing device can be reliably suppressed and attached with high accuracy. In addition, since the bearing device is supported in a state where the cover member that covers the opening of the housing and the other end surface of the shaft are in contact with each other, the bearing device can be supported without interference between the cover member and the rolling bearing. Therefore, when the bearing device is attached to the cover member, it is possible to prevent the preload applied to the pair of rolling bearings from changing.

  A cover member for covering the opening of the housing and supporting the other end of the bearing device; and the bearing device is a second rolling bearing disposed on the other side of the cover member and the axial direction. It is characterized by being supported by the cover member in a state in which the other end surface of the inner ring is in contact.

  According to the present invention, since the bearing device can be supported from both the one side and the other side of the bearing device, the inclination of the bearing device can be reliably suppressed and attached with high accuracy. Further, since the bearing device is supported in a state where the cover member that covers the opening of the housing and the other end surface of the inner ring of the second rolling bearing are in contact with each other, it is possible to attach the bearing device with high accuracy while suppressing the inclination of the bearing device it can.

According to the present invention, the one end surface of the inner ring of the first rolling bearing is flush with the one end surface of the shaft, or protrudes to one side from the one end surface of the shaft. When attached to a mounted body such as a housing of a playback apparatus, the one end surface of the inner ring of the first rolling bearing can be mounted in contact with the mounted body. As a result, the axial length of the bearing device can be shortened by the thickness of the flange portion, compared to the case where the flange portion is brought into contact with a mounted body such as a housing as in the prior art. (Thinning in the axial direction) can be achieved.
Further, in the present invention, the pair of rolling bearings is fixed by being inserted and fixed to the shaft without abutting against the flange portion, respectively, so that the relative relationship between the pair of rolling bearings due to the variation in shape of the flange portion in the prior art is achieved. The occurrence of tilt can be suppressed.
Furthermore, when applying preload, it can be done by abutting one end face of the inner ring of the first rolling bearing against the jig, so the load direction of preload is defined using the one end face of the inner ring of the first rolling bearing as the reference plane. it can. That is, since the one end face of the inner ring of the first rolling bearing and the reference surface that defines the load direction of the preload are the same, even when preload is applied, a pair of shapes caused by the variation in the shape of the flange portion in the prior art Occurrence of the relative inclination of the rolling bearing can be suppressed.
In addition, when attaching the bearing device to the mounted body, one end face of the inner ring of the first rolling bearing can be mounted in contact with the mounted body, resulting in variations in the shape of the flange as in the prior art. And the inclination with respect to the to-be-attached body of a bearing apparatus does not generate | occur | produce. In particular, since the rolling bearing is generally formed with high accuracy, the bearing device is attached to the mounted body by suppressing the inclination of the bearing device by bringing one end face of the inner ring of the first rolling bearing into contact with the mounted body. Can be attached with high accuracy.

1 is a perspective view of an information recording / reproducing apparatus according to an embodiment. It is side surface sectional drawing along the AA of FIG. It is side surface sectional drawing of the bearing apparatus which concerns on 1st embodiment. It is explanatory drawing of the manufacturing process of the bearing apparatus which concerns on 1st embodiment. It is explanatory drawing of an adhesive agent application process. It is explanatory drawing of a 1st rolling bearing insertion process. It is explanatory drawing of a spacer insertion process. It is explanatory drawing of a 2nd rolling bearing insertion process. It is explanatory drawing of a preload addition process. It is side surface sectional drawing of the bearing apparatus which concerns on the modification of 1st embodiment. It is side surface sectional drawing of the bearing apparatus which concerns on 2nd embodiment. It is side surface sectional drawing of the bearing apparatus which concerns on the modification of 2nd embodiment. It is side surface sectional drawing of the bearing apparatus which concerns on 3rd embodiment. It is side surface sectional drawing of the bearing apparatus which concerns on the modification of 3rd embodiment.

  The bearing device, the manufacturing method of the bearing device, and the information recording / reproducing device according to the first embodiment will be described below. In the following, after describing the information recording / reproducing apparatus according to the embodiment, the bearing device according to the first embodiment and the method of manufacturing the bearing device will be described.

(Information recording / reproducing device)
FIG. 1 is a perspective view of an information recording / reproducing apparatus 1 according to the embodiment. In FIG. 1, the housing 9 and the cover member 12 that covers the opening of the housing 9 are illustrated by a two-dot chain line.
FIG. 2 is a side sectional view taken along line AA in FIG.
As shown in FIG. 1, the information recording / reproducing apparatus 1 is an apparatus that writes and reads data on a disk (magnetic recording medium) D having a recording layer. The information recording / reproducing apparatus 1 includes an arm (rotating member) 8, a head gimbal assembly 4 supported on the tip side of the arm 8, a slider 2 attached to the tip of the head gimbal assembly 4, and a head gimbal assembly 4. An actuator (VCM: voice coil motor) 6 for moving the scan, a spindle motor 7 for rotating the disk D, a control unit 5 for supplying a current modulated in accordance with information to the slider 2, and these components are housed inside. And a cover member 12 that closes the opening of the housing 9.

  The housing 9 is made of a metal material such as aluminum, iron, or stainless steel, and has a box shape with an opening at the top. The housing 9 stands vertically from the rectangular bottom 9a and the peripheral edge of the bottom 9a. It is comprised with the surrounding wall 9b provided. A housing recess for housing the above-described components is formed inside the housing 9 surrounded by the peripheral wall 9b. A spindle motor 7 is attached to substantially the center of the bottom portion 9a, and the disc D is detachably fixed by fitting a center hole into the spindle motor 7.

A bearing device 10 is disposed on the side of the disk D. As shown in FIG. 2, an arm 8 is externally fixed to the outer peripheral surface of the bearing device 10. As shown in FIG. 1, the base end portion of the arm 8 is connected to the actuator 6 described above. Further, the arm 8 extends in parallel with the surface of the disk D from the proximal end side toward the distal end side.
A head gimbal assembly 4 is connected to the tip of the arm 8. The head gimbal assembly 4 includes a suspension 3 and a slider 2 that is attached to the tip of the suspension 3 and is disposed to face the surface of the disk D. The slider 2 includes a recording element for writing (recording) information on the disk D and a reproducing element for reading (reproducing) information from the disk D.

  In the information recording / reproducing apparatus 1 configured as described above, in order to record or reproduce information, the spindle motor 7 is first driven to rotate the disk D around the central axis L2 of the disk D. Further, the actuator 6 is driven to rotate the arm 8 around the bearing device 10 as the rotation center. As a result, the slider 2 disposed at the tip of the head gimbal assembly 4 can be scanned and moved to each part of the surface of the disk D. Then, by driving the recording element or reproducing element of the slider 2, information can be recorded or reproduced on the disk D.

(First embodiment)
FIG. 3 is a side cross-sectional view of the bearing device 10 according to the first embodiment. Hereinafter, a direction along the axis of the bearing device 10 (that is, the axis of the shaft 20, hereinafter referred to as “center axis L <b> 1”) is referred to as “axial direction”. Further, in the axial direction, the bottom 9a side (that is, the lower side in FIG. 3) of the housing 9 shown in FIG. 1 is referred to as one side, and the opening side (that is, the upper side in FIG. 3) of the housing 9 is referred to as the other side. Further, a direction orthogonal to the central axis L1 is referred to as a “radial direction”, and a direction around the central axis L1 is referred to as a “circumferential direction”.
As shown in FIG. 3, the bearing device 10 according to the first embodiment includes a shaft 20, a pair of rolling bearings 30 and 40 that are extrapolated to the shaft 20 and arranged in the axial direction of the shaft 20, and a pair And a cylindrical spacer 70 disposed between the rolling bearings 30 and 40.

(shaft)
The shaft 20 includes, for example, a main body portion 21 formed in a substantially cylindrical shape with a metal material such as aluminum, iron, and stainless steel, and a flange portion 25 formed in the vicinity of an intermediate portion in the axial direction of the main body portion 21. Yes.
A female thread is formed on the inner peripheral surface 23 of the main body 21. As shown in FIG. 2, the shaft 20 is supported on the bottom portion 9 a of the housing 9 by the bolt 13 being screwed onto the inner peripheral surface 23 of the shaft 20 from one side via the bottom portion 9 a of the housing 9. The shaft 20 is supported by the cover member 12 by the bolts 14 being screwed onto the inner peripheral surface 23 of the shaft 20 from the other side via the cover member 12.

As shown in FIG. 3, the flange portion 25 is formed so as to protrude outward in the radial direction from a portion of one side of the outer peripheral surface 22 of the main body portion 21 in the axial direction. The flange portion 25 of the present embodiment is formed over the entire circumference of the main body portion 21 in the circumferential direction.
The outer diameter of the flange portion 25 is formed to be smaller than the outer diameter of the inner ring 36 of the first rolling bearing 30 disposed on one side of a pair of rolling bearings 30 and 40 described later.
Moreover, the axial thickness of the flange 25 is formed to be thinner than the axial thickness of a spacer 70 described later.

  The other side end surface 36b of the inner ring 36 of the first rolling bearing 30 described later is in contact with the one side surface 25a of the flange portion 25. The separation distance along the axial direction between the one side surface 25 a of the flange portion 25 and the one side end surface 24 a of the shaft 20 is formed to be shorter than the axial length of the first rolling bearing 30. Moreover, the separation distance along the axial direction between the other side surface 25b of the flange 25 and the other side end surface 24b of the shaft 20 is longer than the axial length of the second rolling bearing 40 described later disposed on the other side. It is formed to become.

(First rolling bearing)
A first rolling bearing 30 is disposed on one axial side of the shaft 20. The first rolling bearing 30 includes an inner ring 36 fixed to the shaft 20, an outer ring 31 surrounding the inner ring 36, and a plurality of rolling elements 35 disposed between the inner ring 36 and the outer ring 31. The plurality of rolling elements 35 are held by a retainer (not shown) so as to be substantially equidistant in the circumferential direction and capable of rolling.

The inner ring 36 is formed in a substantially cylindrical shape from a metal material such as stainless steel.
A rolling groove 39 is formed in the axial intermediate portion of the outer peripheral surface 37 of the inner ring 36. The rolling groove 39 is formed over the entire circumference of the outer circumferential surface 37 of the inner ring 36. The inner surface of the rolling groove 39 is a rolling surface 39a, and the cross section of the rolling surface 39a is formed in an arc shape.
The inner diameter of the inner ring 36 is formed so as to be dimensioned so that it can be extrapolated to the main body 21 of the shaft 20. In the present embodiment, the inner diameter of the inner ring 36 is formed to be slightly larger than the outer diameter of the main body portion 21 of the shaft 20. The inner ring 36 is extrapolated to the shaft 20 and is fixed to the shaft 20 with, for example, an adhesive. The inner diameter of the inner ring 36 may be formed to be the same as or slightly smaller than the outer diameter of the main body portion 21 of the shaft 20. In this case, the inner ring 36 is externally inserted into the shaft 20 and is press-fitted and fixed.

As with the inner ring 36, the outer ring 31 is formed in a substantially cylindrical shape from a metal material such as stainless steel.
A rolling groove 34 is formed in an intermediate portion in the axial direction on the inner peripheral surface 33 of the outer ring 31. The rolling groove 34 is formed over the entire circumference of the inner circumferential surface 33 of the outer ring 31. The inner surface of the rolling groove 34 is a rolling surface 34a, and the cross section of the rolling surface 34a is formed in an arc shape.

  The rolling element 35 is formed in a spherical shape from a metal material. The rolling element 35 is disposed inside the rolling groove 34 of the outer ring 31 and the rolling groove 39 of the inner ring 36, and rolls along the rolling grooves 34 and 39. The radius of curvature of each rolling surface 34a, 39a of each rolling groove 34, 39 is formed to be equal to the radius of curvature of the outer surface of the rolling element 35.

  The first rolling bearing 30 is extrapolated to the shaft 20 from one side of the shaft 20, and is abutted against the flange portion 25 in a state where the other side end surface 36 b of the inner ring 36 and the one side surface 25 a of the flange portion 25 are in contact with each other. Arranged. Here, as described above, the separation distance between the one side surface 25a of the flange portion 25 and the one side end surface 24a of the shaft 20 is formed to be shorter than the length of the first rolling bearing 30 in the axial direction. Therefore, the one end surface 36 a of the inner ring 36 of the first rolling bearing 30 protrudes to the one side from the one end surface 24 a of the shaft 20.

(Second rolling bearing)
A second rolling bearing 40 is disposed on the other side of the shaft 20 in the axial direction. The second rolling bearing 40 includes an inner ring 46 fixed to the shaft 20, an outer ring 41 surrounding the inner ring 46, and a plurality of rolling elements 45 disposed between the inner ring 46 and the outer ring 41. In this embodiment, since the 2nd rolling bearing 40 is formed in the same shape as the 1st rolling bearing 30, detailed description is abbreviate | omitted. The second rolling bearing 40 is disposed by being extrapolated to the shaft 20 from the other side of the shaft 20.

(Spacer)
The spacer 70 is formed in a cylindrical shape from a metal material such as aluminum, iron, or stainless steel. The outer diameter of the spacer 70 is formed to be substantially the same as the outer diameter of the outer ring 31 of the first rolling bearing 30 and the outer ring 41 of the second rolling bearing 40. The inner diameter of the spacer 70 is formed to be smaller than the inner diameter of the outer ring 31 of the first rolling bearing 30 and the outer ring 41 of the second rolling bearing 40.
The thickness (length) in the axial direction of the spacer 70 is formed so as to be thicker than the thickness in the axial direction of the flange portion 25 of the shaft 20.

  Further, in the present embodiment, in a state where the one end surface 70a of the spacer 70 is disposed in contact with the other end surface 31b of the outer ring 31 of the first rolling bearing 30, the other end surface 70b of the spacer 70 and the shaft 20 are disposed. The separation distance along the axial direction of the other end surface 24b of the second rolling bearing 40 is longer than the axial length of the second rolling bearing 40. Therefore, when the one end surface 41 a of the outer ring 41 of the second rolling bearing 40 is brought into contact with the other end surface 70 b of the spacer 70 and disposed on the shaft 20, the other end surface 24 b of the shaft 20 is disposed on the second rolling bearing 40. The inner ring 46 protrudes to the other side of the other end surface 46b.

  The first rolling bearing 30 and the second rolling bearing 40 are in a state in which preload is relatively applied in the axial direction of the shaft 20. In the present embodiment, the inner ring 46 of the second rolling bearing 40 is fixed to the shaft 20 in a state of being pressed toward one side (that is, the first rolling bearing 30 side), whereby the first rolling bearing 30 and the first rolling bearing 30. A preload is applied relative to the double rolling bearing 40. The addition of the preload will be described in the bearing device manufacturing method described later.

As shown in FIG. 2, the bearing device 10 configured as described above has one side end fastened to and supported by a bolt 13 on the bottom 9 a of the housing 9, and the other side end fastened to the cover member 12 by a bolt 14. And is incorporated in the information recording / reproducing apparatus 1.
Here, since the one end surface 36 a of the inner ring 36 of the first rolling bearing 30 protrudes to the one side from the one end surface 24 a of the shaft 20, the one end portion of the bearing device 10 is the bottom portion 9 a of the housing 9. And the one end face 36a of the inner ring 36 of the first rolling bearing 30 is supported by the housing 9 in a contact state. Accordingly, the bearing device 10 can be attached to the housing 9 with high accuracy while suppressing the inclination of the bearing device 10 with respect to the vertical direction of the housing 9.

  Furthermore, since the other end surface 24b of the shaft 20 protrudes to the other side from the other end surface 46b of the inner ring 46 of the second rolling bearing 40, the other end portion of the bearing device 10 is the other end surface of the shaft 20. 24b and the cover member 12 are supported by the cover member 12 in a contact state. Thereby, since the bearing apparatus 10 can be supported from the both sides of the one side and the other side of the bearing apparatus 10, the inclination of the bearing apparatus 10 can be reliably suppressed and attached with high accuracy. Further, since the bearing device is supported in a state where the cover member 12 and the other end surface 24b of the shaft 20 are in contact with each other, the bearing device 10 is supported without interference between the cover member 12 and the second rolling bearing 40. it can. Therefore, when the bearing device 10 is attached to the cover member 12, it is possible to prevent the preload applied to the pair of rolling bearings 30 and 40 from changing.

(Bearing device manufacturing method)
Then, the manufacturing method of the bearing apparatus 10 of this embodiment is demonstrated.
FIG. 4 is a flowchart of the manufacturing process (manufacturing method) of the bearing device 10.
As shown in FIG. 4, the manufacturing process of the bearing device 10 includes an adhesive application process S11, a first rolling bearing insertion process S13, a spacer insertion process S15, a second rolling bearing insertion process S17, and a preload application process S19. And. Below, each process is demonstrated.

(Adhesive application step S11)
FIG. 5 is an explanatory diagram of the adhesive application step S11.
First, as shown in FIG. 5, adhesives for fixing the inner ring 36 of the first rolling bearing 30 and the inner ring 46 of the second rolling bearing 40 (refer to FIG. 3) to the outer peripheral surface 22 of the shaft 20. An adhesive application step S11 to be applied is performed. For example, an anaerobic adhesive is suitable as the adhesive applied in the adhesive application step S11.
In the adhesive application step S11, while applying the adhesive to the region 22a on the one side of the outer peripheral surface 22 of the shaft 20 to which the inner ring 36 (see FIG. 3) of the first rolling bearing 30 is fixed, Adhesive is also applied to the region 22b on the other side of the flange 25 where the inner ring 46 (see FIG. 3) of the second rolling bearing 40 is fixed. That is, in the adhesive application step S <b> 11, the adhesive is simultaneously applied to the region 22 a on one side of the flange 25 and the region 22 b on the other side of the flange 25. Above, adhesive application process S11 is complete | finished.

(First rolling bearing insertion step S13)
FIG. 6 is an explanatory diagram of the first rolling bearing insertion step S13.
Then, as shown in FIG. 6, after apply | coating an adhesive agent by adhesive agent application process S11, 1st rolling bearing insertion process S13 which extrapolates the 1st rolling bearing 30 to the shaft 20 is performed. In the first rolling bearing insertion step S <b> 13, the first rolling bearing 30 is inserted into the shaft 20 from one side of the shaft 20 toward the other side. And it pushes in until the other side end surface 36b of the inner ring | wheel 36 of the 1st rolling bearing 30 contact | abuts to the one side surface 25a of the collar part 25. FIG. Above, 1st rolling bearing insertion process S13 is complete | finished.

(Spacer insertion step S15)
FIG. 7 is an explanatory diagram of the spacer insertion step S15.
Subsequently, as shown in FIG. 7, a spacer insertion step S <b> 15 for inserting the spacer 70 into the shaft 20 is performed. In the spacer insertion step S15, the spacer 70 is inserted into the shaft 20 from the other side of the shaft 20 to the one side, and the one end surface 70a of the spacer 70 is brought into contact with the other end surface 31b of the outer ring 31 of the first rolling bearing 30. Make contact. Thus, the spacer insertion step S15 is completed.

(Second rolling bearing insertion step S17)
FIG. 8 is an explanatory diagram of the second rolling bearing insertion step S17.
Then, as shown in FIG. 8, the 2nd rolling bearing insertion process S17 which extrapolates the 2nd rolling bearing 40 to the shaft 20 is performed. In the second rolling bearing insertion step S <b> 17, the second rolling bearing 40 is inserted into the shaft 20 from the other side of the shaft 20 toward the one side. And it pushes in until the one side end surface 41a of the outer ring | wheel 41 of the 2nd rolling bearing 40 contact | abuts to the other side end surface 70b of the spacer 70. FIG. Above, 2nd rolling bearing insertion process S17 is complete | finished.

(Preload application step S19)
FIG. 9 is an explanatory diagram of the preload adding step S19.
Subsequently, as shown in FIG. 9, a preload application step S <b> 19 is performed for applying a preload along the axial direction to the first rolling bearing 30 and the second rolling bearing 40. As shown in FIG. 4, the preload adding step S19 of the present embodiment includes a preload jig placement step S19A and a pressing step S19B. Below, each process of preload addition process S19 is demonstrated.

(Preload jig placement step S19A)
As shown in FIG. 9, in the preload application step S19, first, a preload jig placement step S19A for placing a preload jig 90 on one side of the shaft 20 is performed.
The preloading jig 90 includes a base portion 90a formed in a disc shape, and a columnar protrusion portion 90b that is arranged concentrically with the base portion 90a and protrudes from the main surface of the base portion 90a. The outer diameter of the base portion 90 a is formed to be substantially the same as the outer diameter of the inner ring 36 of the first rolling bearing 30. The outer diameter of the projecting portion 90 b is slightly smaller than the inner diameter of the shaft 20 so that it can be inserted inside the shaft 20.
In the preload jig placement step S19A, the base portion 90a is positioned on the first rolling bearing 30 while the protrusion 90b of the preload jig 90 is inserted from one side of the shaft 20 to position the shaft 20 and the preload jig 90. A preload jig 90 is disposed on one side of the shaft 20 in contact with one end surface 36 a of the inner ring 36.

(Pressing step S19B)
Subsequently, in the preload adding step S19, a pressing step S19B for pressing the second rolling bearing 40 using the pressing jig 92 is performed.
The pressing jig 92 is a crested cylindrical jig having a top surface on the other side. The inner diameter of the cylindrical portion 92 a of the pressing jig 92 is formed to be larger than the outer diameter of the shaft 20. Further, the outer diameter of the cylindrical portion 92 a of the pressing jig 92 is formed to be substantially the same as the outer diameter of the inner ring 46 of the second rolling bearing 40. Thereby, the end surface of the cylindrical portion 92 a of the pressing jig 92 can be brought into contact with the other end surface 46 b of the inner ring 46 of the second rolling bearing 40.
In the pressing step S19B, the second rolling bearing is directed from the other side toward the one side in a state where the end surface of the cylindrical portion 92a of the pressing jig 92 is in contact with the other end surface 46b of the inner ring 46 of the second rolling bearing 40. The 40 inner rings 46 are pressed along the axial direction with a predetermined load.

By pressing the inner ring 46 of the second rolling bearing 40, the distance between the inner ring 36 of the first rolling bearing 30 and the inner ring 46 of the second rolling bearing 40 is shortened, but the outer ring 31 of the first rolling bearing 30 and The distance between the second rolling bearing 40 and the outer ring 41 is maintained by the spacer 70. Thereby, the outer ring 41 of the second rolling bearing 40 is shifted to the other side relative to the inner ring 46 of the second rolling bearing 40.
The outer ring 41 of the second rolling bearing 40 presses the outer ring 31 of the first rolling bearing 30 from the other side toward the one side via the spacer 70. As a result, the outer ring 31 of the first rolling bearing 30 is shifted to one side relative to the inner ring 36 of the first rolling bearing 30.
Thus, preload is applied to the first rolling bearing 30 and the second rolling bearing 40 by pressing the inner ring 46 of the second rolling bearing 40 along the axial direction from the other side to the one side. Then, the inner ring 46 of the second rolling bearing 40 is pressed until the adhesive is cured.
When the adhesive is cured, the preload application step S19 is completed and the manufacturing process of the bearing device 10 is completed, and the bearing device 10 according to the present embodiment is completed.

(Modification of the first embodiment)
FIG. 10 is a side sectional view of a bearing device 10 according to a modification of the first embodiment.
Then, the bearing apparatus 10 which concerns on the modification of 1st embodiment is demonstrated.
The bearing device 10 of the first embodiment is formed by extrapolating a first rolling bearing 30 and a second rolling bearing 40 to a shaft 20 (see FIG. 3).
On the other hand, as shown in FIG. 10, in the bearing device 10 according to the modification of the first embodiment, the first rolling bearing 30 and the second rolling bearing 40 are extrapolated to the shaft 20, and further the first rolling bearing. 30 and the second rolling bearing 40 are different from the bearing device 10 of the first embodiment in that a sleeve 50 is extrapolated. In addition, description is abbreviate | omitted about the component similar to 1st embodiment, and only a different part is demonstrated.

The sleeve 50 is a cylindrical member formed of a metal material such as aluminum, iron, or stainless steel. The inner diameter of the sleeve 50 is formed to be larger than the outer diameters of the first rolling bearing 30 and the second rolling bearing 40 so that the sleeve 50 can be extrapolated to the first rolling bearing 30 and the second rolling bearing 40. The sleeve 50 is fixed to the first rolling bearing 30 and the second rolling bearing 40 with, for example, an adhesive. The sleeve 50 of this modification is integrally formed with the spacer 70.
By providing the sleeve 50, the outer peripheral surface of the bearing device 10 can be formed without a step, and the outer diameter of the bearing device 10 can be made uniform. Therefore, since the arm 8 (see FIG. 1) can be mounted with high precision on the bearing device 10, a high-performance information recording / reproducing apparatus 1 (see FIG. 1) can be formed.

(Effects of the first embodiment and the modification of the first embodiment)
According to the first embodiment and the modification of the first embodiment, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 protrudes to the one side from the one end surface 24a of the shaft 20, and thus the bearing device. 10 is attached to the bottom 9 a of the housing 9 of the information recording / reproducing apparatus 1, the one end surface 36 a of the inner ring 36 of the first rolling bearing 30 can be attached to the bottom 9 a of the housing 9. Thus, the axial length of the bearing device 10 can be shortened by the thickness of the flange portion, compared to the case where the flange portion is brought into contact with the attached body such as the housing 9 as in the prior art. Can be reduced in size (thinning in the axial direction).
Further, when applying the preload, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 can be abutted against the preloading jig 90, so the one end surface 36a of the inner ring 36 of the first rolling bearing 30 is used as a reference. The preload direction can be defined as a surface. That is, since the one end surface 36a of the inner ring 36 of the first rolling bearing 30 is the same as the reference surface that defines the load direction of the preload, it is caused by the variation in the shape of the flange portion in the prior art even when preload is applied. The occurrence of relative inclination of the pair of rolling bearings 30 and 40 can be suppressed.
Further, when the bearing device 10 is attached to the bottom portion 9a of the housing 9, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 can be attached to the bottom portion 9a of the housing 9 so that it can be attached as in the prior art. Furthermore, the inclination of the bearing device 10 with respect to the housing 9 does not occur due to the variation in the shape of the collar portion. In particular, since the rolling bearing is generally formed with high accuracy, the inclination of the bearing device 10 is suppressed by bringing the one end surface 36a of the inner ring 36 of the first rolling bearing 30 into contact with the bottom 9a of the housing 9. The bearing device 10 can be attached to the housing 9 with high accuracy.

In addition, the flange portion 25 protruding outward in the radial direction of the shaft 20 between the pair of rolling bearings 30 and 40 is formed thinner than the thickness of the spacer 70 disposed between the pair of rolling bearings 30 and 40. Therefore, the overall length of the bearing device 10 is not affected. Therefore, the bearing device 10 can be prevented from being enlarged due to the formation of the flange portion 25, and the bearing device 10 can be downsized (thinned in the axial direction).
Further, when the other end face 36b of the inner ring 36 of the first rolling bearing 30 is brought into contact with the flange 25, the positioning of the first rolling bearing 30 with respect to the shaft 20 can be facilitated when the bearing device 10 is manufactured.
Further, when the bearing device 10 is attached with the one end surface 36a of the inner ring 36 of the first rolling bearing 30 in contact with the bottom 9a of the housing 9, the first rolling bearing 30 is connected to the bottom 9a and the flange 25 of the housing 9. It will be in the state pinched by. Thereby, when the bearing device 10 is fixed to the bottom portion 9 a of the housing 9 with the bolt 13, a sufficient axial force can be applied, so that the bearing device 10 can be firmly fixed to the housing 9.

  Moreover, according to the manufacturing method of the bearing device of the present embodiment, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 protrudes to the one side from the one end surface 24a of the shaft 20, so that the preload jig 90, the inner ring 36 of the first rolling bearing 30 and the inner ring 46 of the second rolling bearing 40 can be relatively pressed in a state where the one end surface 36a of the inner ring 36 of the first rolling bearing 30 is securely brought into contact with 90. . Therefore, since a preload can be reliably applied to the pair of rolling bearings 30 and 40, it is possible to manufacture a high-performance bearing device 10 that can reduce vibration during rotation and suppress torque ripple.

Here, in general, an anaerobic adhesive is used for fixing the shaft 20 and the inner ring 36 of the first rolling bearing 30 and the inner ring 46 of the second rolling bearing 40. In the prior art, after simultaneously applying an adhesive to a region where one rolling bearing is fixed and a region where the other rolling bearing is fixed on the outer peripheral surface of the shaft, when one rolling bearing is inserted into the shaft, the other The adhesive may be dragged when passing through the region where the rolling bearing is fixed, and may adhere to the region between the pair of rolling bearings on the outer peripheral surface of the shaft. Thereby, there exists a possibility that an adhesive agent cannot be hardened | cured in the area | region between a pair of rolling bearings among the outer peripheral surfaces of a shaft. Further, when the bearing device is incorporated into an information recording / reproducing apparatus, for example, with the adhesive remaining uncured, outgas is generated from the adhesive and adheres to the surface of the slider, and information is transferred between the slider and the magnetic recording medium. When performing recording and reproduction, there is a risk that recording failure and reproduction failure may occur. Therefore, conventionally, after applying an adhesive on one side of the outer peripheral surface of the shaft and fixing one side rolling bearing, apply an adhesive on the other side of the outer peripheral surface of the shaft and fixing the other side rolling bearing. Was. That is, the adhesive application process is divided into two processes.
On the other hand, according to the present invention, since the flange portion 25 is provided between the pair of rolling bearings 30 and 40, the rolling bearings 30 and 40 are respectively inserted from both sides of the shaft 20 on one side and the other side. it can. Thereby, when the 1st rolling bearing 30 and the 2nd rolling bearing 40 are each inserted in the shaft 20, the 1st rolling bearing 30 does not pass the area | region 22b of the other side which fixes the 2nd rolling bearing 40, Since the second rolling bearing 40 does not pass through the one side region 22 a that fixes the first rolling bearing 30, the adhesive is a region between the pair of rolling bearings 30, 40 in the outer peripheral surface 22 of the shaft 20. Can be prevented. Therefore, since the adhesive application step S11 can be performed in one step, the manufacturing time of the bearing device 10 can be shortened and the productivity of the bearing device 10 can be improved.

  Further, according to the information recording / reproducing apparatus 1 of the present embodiment, the bottom portion 9a of the housing 9 and the one end surface 36a of the inner ring 36 of the first rolling bearing 30 are supported by the housing 9 in contact with each other. The inclination of the bearing device 10 with respect to the housing 9 due to the variation in the shape of the flange portion in the prior art does not occur. In particular, since the rolling bearing is generally formed with high accuracy, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 is brought into contact with the bottom 9a of the housing 9, thereby suppressing the inclination of the bearing device 10, The bearing device 10 can be attached to the housing 9 with high accuracy. Therefore, it is possible to obtain a high-performance information recording / reproducing apparatus 1 that is small and can record and reproduce information satisfactorily.

  Further, since the bearing device 10 can be supported from both the one side and the other side of the bearing device 10, the inclination of the bearing device 10 can be reliably suppressed and attached with high accuracy. Further, since the bearing device 10 is supported in a state where the cover member 12 covering the opening of the housing 9 and the other end surface 24b of the shaft 20 are in contact with each other, the cover member 12 and the second rolling bearing 40 interfere with each other. The bearing device 10 can be supported without any problems. Therefore, when the bearing device 10 is attached to the cover member 12, it is possible to prevent the preload applied to the pair of rolling bearings 30 and 40 from changing.

(Second embodiment)
Below, the bearing apparatus 210 which concerns on 2nd embodiment is demonstrated.
FIG. 11 is a side sectional view of the bearing device 210 according to the second embodiment.
In the bearing device 10 of the first embodiment, a flange portion 25 is formed in the vicinity of the intermediate portion of the shaft 20 so as to project outward in the radial direction (see FIG. 3).
On the other hand, as shown in FIG. 11, the bearing device 210 according to the second embodiment is different in that a flange portion 225 that projects outward in the radial direction is formed at one end portion of the shaft 220. This is different from the bearing device 10 of the embodiment. In addition, description is abbreviate | omitted about the component similar to 1st embodiment, and only a different part is demonstrated.

The flange portion 225 is formed over the entire circumference of the main body portion 21 at one end portion of the shaft 220, and the outer diameter (outer shape) thereof is smaller than the outer diameter of the inner ring 36 of the first rolling bearing 30, for example. It is formed as follows.
On one end face 36 a of the inner ring 36 of the first rolling bearing 30, a recess 236 into which the flange 225 can be fitted is formed at a position corresponding to the flange 225. The recess 236 is formed by denting the inner edge of one side of the inner ring 36 from one side to the other side.

  The shape of the concave portion 236 is formed in a shape corresponding to the flange portion 225 when viewed in the axial direction. In addition, the depth of the recess 236 is formed to be deeper than the thickness dimension of the flange portion 225. Thereby, when the flange part 225 is fitted in the recessed part 236 and the flange part 225 is disposed in the recessed part 236, the one end face 36 a of the inner ring 36 of the first rolling bearing 30 is more than the one end face 24 a of the shaft 220. Also protrudes to one side.

(Modification of the second embodiment)
FIG. 12 is a side sectional view of a bearing device 210 according to a modification of the second embodiment.
As shown in FIG. 12, a sleeve 50 may be extrapolated to the first rolling bearing 30 and the second rolling bearing 40 as in the modification of the first embodiment. According to the modification of the second embodiment, similarly to the modification of the first embodiment, by providing the sleeve 50, the outer peripheral surface of the bearing device 210 can be formed without any step, and the outer diameter of the bearing device 210 is uniform. It can be. Therefore, the arm 8 (see FIG. 1) can be accurately mounted on the bearing device 210, and the high-performance information recording / reproducing apparatus 1 (see FIG. 1) can be formed.

(Effects of the second embodiment and the modification of the second embodiment)
According to the second embodiment and the modification of the second embodiment, the one end face 36a of the inner ring 36 of the first rolling bearing 30 is a recess into which the flange portion 225 can be fitted at a position corresponding to the flange portion 225. 236 is formed, the flange portion 225 is fitted and disposed in the recess 236 to prevent the bearing device 210 from being enlarged due to the flange portion 225, and the bearing device 210 can be downsized. (Thinning in the axial direction) can be achieved.
Further, by fitting the flange portion 225 into the recess 236 of the inner ring 36 of the first rolling bearing 30, the positioning of the first rolling bearing 30 with respect to the shaft 210 can be facilitated when the bearing device 210 is manufactured.

(Third embodiment)
FIG. 13 is a side sectional view of the bearing device 310 according to the third embodiment.
In the bearing device 10 of the first embodiment, a flange portion 25 is formed in the vicinity of the intermediate portion of the shaft 20 so as to project outward in the radial direction (see FIG. 3). Further, in the bearing device 210 of the second embodiment, a flange portion 225 projecting radially outward is formed at one end portion of the shaft 220 (see FIG. 11).
On the other hand, as shown in FIG. 13, the bearing device 310 according to the third embodiment is the same as that of the first embodiment in that the outer diameter of the shaft 320 is uniformly formed over the entire axial direction. This is different from the bearing device 10 and the bearing device 210 of the second embodiment. In addition, description is abbreviate | omitted about the component similar to 1st embodiment and 2nd embodiment, and only a different part is demonstrated.

As shown in FIG. 13, the bearing device 310 according to the third embodiment has the same outer diameter of the shaft 320 in the axial direction and is formed uniformly.
In the manufacturing process of the bearing device 310 of the third embodiment, for example, a treatment (not shown) is performed so that the one end surface 36a of the inner ring 36 of the first rolling bearing 30 protrudes to one side from the one end surface 24a of the shaft 320. The first rolling bearing insertion step S13 (see FIG. 6) is performed while positioning the relative position of the shaft 320 and the first rolling bearing 30 in the axial direction with the tool.

(Modification of the third embodiment)
FIG. 14 is a side sectional view of a bearing device 310 according to a modification of the third embodiment.
As shown in FIG. 14, a sleeve 50 may be extrapolated to the first rolling bearing 30 and the second rolling bearing 40 in the same manner as the modification of the first embodiment and the modification of the second embodiment. According to the modification of the third embodiment, as with the modification of the first embodiment and the modification of the second embodiment, by providing the sleeve 50, the outer peripheral surface of the bearing device 310 can be formed without a step, and the bearing The outer diameter of the device 310 can be made uniform. Accordingly, since the arm 8 (see FIG. 1) can be mounted with high precision on the bearing device 310, a high-performance information recording / reproducing apparatus 1 (see FIG. 1) can be formed.

(Effects of the third embodiment and the modification of the third embodiment)
According to the third embodiment and the modification of the third embodiment, since the shaft 320 can be easily formed, the shaft 320 can be reduced in size (thinned in the axial direction) and the relative inclination of the pair of rolling bearings 30 and 40 can be generated. The bearing device 310 that can be suppressed and can be attached with high accuracy while suppressing inclination can be formed at low cost.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

In each embodiment and the modification of each embodiment, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 protrudes to the one side from the one end surface 24a of the shafts 20, 220, and 320. On the other hand, for example, the one end surface 36a of the inner ring 36 of the first rolling bearing 30 and the one end surface 24a of the shafts 20, 220, and 320 may be formed flush with each other.
In addition to the fact that one end surface 36a of the inner ring 36 of the first rolling bearing 30 protrudes to one side from the one end surface 24a of the shafts 20, 220, 320, the other side of the inner ring 46 of the second rolling bearing 40. The end surface 46b may protrude to the other side from the other side end surface 24b of the shafts 20, 220, and 320. Thereby, since the bearing device 10, 210, 310 can be supported in a state where the cover member 12 and the other end surface 46b of the inner ring 46 of the second rolling bearing 40 are in contact with each other, the bearing device 10, 210, 310 can be inclined. It can be suppressed and attached with high accuracy.

  In each embodiment and the modification of each embodiment, the other side end surface 24b of the shafts 20, 220, 320 protrudes to the other side of the other side end surface 46b of the inner ring 46 of the second rolling bearing 40. On the other hand, for example, the other end surface 24b of the shafts 20, 220, and 320 may not protrude to the other side from the other end surface 46b of the inner ring 46 of the second rolling bearing 40. However, the other end surface 24b of the shaft 20, 220, 320 is projected to the other side from the other end surface 46b of the inner ring 46 of the second rolling bearing 40, thereby covering the other end surface 24b of the shaft 20, 220, 320 and the cover. The other end of the shaft 20, 220, 320 can be supported by contacting the member 12. Thereby, the bearing device 10, 210, 310 can be attached to the housing 9 with high accuracy by suppressing the inclination of the bearing device 10, 210, 310 with respect to the vertical direction of the housing 9. The modification has an advantage.

In the modification of each embodiment, the sleeve 50 is integrally formed with the spacer 70. On the other hand, for example, the sleeve 50 may be formed separately from the spacer 70. However, the modification of each embodiment is advantageous in that the number of parts can be reduced and the sleeve 50 and the spacer 70 can be formed at low cost.
Further, the outer ring 31 of the first rolling bearing 30 and the outer ring 41 of the second rolling bearing 40 are formed thicker (longer) in the axial direction than the inner ring 36 of the first rolling bearing 30 and the inner ring 46 of the second rolling bearing 40, respectively. And the spacers 70 may be deleted. Further, the outer ring 31 of the first rolling bearing 30 and the outer ring 41 of the second rolling bearing 40 may be integrally formed with each other. Thereby, since the spacer 70 can be abolished, the bearing apparatus 10 can be formed at low cost.

  In the first embodiment, the bearing device 10 is applied as the pivot shaft of the arm 8 of the information recording / reproducing apparatus 1. However, the application of the bearing device 10 is limited to the pivot shaft of the arm 8 of the information recording / reproducing apparatus 1. Not. For example, the bearing device 10 may be applied as the rotating shaft of the spindle motor 7 that rotates the disk D of the information recording / reproducing apparatus 1, or the bearing device 10 is applied as the rotating shaft of the polygon mirror for scanning the laser light source. May be.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Information recording / reproducing apparatus 2 ... Slider 8 ... Arm (rotating member) 9 ... Housing 9a ... Bottom part 10 ... Bearing apparatus 12 ... Cover member 20,220,320 ... shaft 22 ... outer peripheral surface 22a ... one side area 22b ... other side area 24a ... one side end face of the shaft 25 ... collar 30, 40 ... pair Rolling bearing 30 ... 1st rolling bearing 36 ... Inner ring 36a of the first rolling bearing 36a ... One end face of the inner ring of the first rolling bearing 36b ... End face of the other side of the inner ring of the first rolling bearing 40 ... Second rolling bearing 46 ... Inner ring of second rolling bearing 90 ... Preloading jig 225 ... Flange part 236 ... Recessed part D ... Disk (magnetic recording medium) S11 ... Adhesion Agent coating process 19 ... preload addition step S19A ... preload jig disposing step S19b ... pressing step

Claims (11)

A shaft,
A pair of rolling bearings extrapolated to the shaft and arranged side by side in the axial direction of the shaft,
Each of the pair of rolling bearings includes an inner ring fixed to the shaft,
Of the pair of rolling bearings, the one end surface of the inner ring of the first rolling bearing disposed on one side in the axial direction is flush with the one end surface of the shaft or more than the one end surface of the shaft. A bearing device that protrudes toward the one side. The bearing device according to claim 1,
The shaft includes a flange portion that projects outward in the radial direction of the shaft between the pair of rolling bearings,
2. The bearing device according to claim 1, wherein the flange portion is in contact with the other end surface of the inner ring of the first rolling bearing. The bearing device according to claim 2,
A cylindrical spacer is provided between the pair of rolling bearings,
The bearing device is characterized in that a thickness of the flange portion in the axial direction is formed thinner than a thickness of the spacer in the axial direction. The bearing device according to claim 1,
The shaft includes a flange portion projecting radially outward of the shaft at one end portion of the shaft,
A bearing device in which a concave portion into which the flange portion can be fitted is formed at a position corresponding to the flange portion on one end face of the inner ring of the first rolling bearing. The bearing device according to claim 1,
The outer diameter of the shaft is uniformly formed over the entire axial direction. The bearing device according to any one of claims 1 to 5,
The other side end surface of the inner ring of the second rolling bearing disposed on the other side in the axial direction is flush with the other side end surface of the shaft, or protrudes to the other side from the other side end surface of the shaft. A bearing device. It is a manufacturing method of the bearing device according to claim 1, Comprising:
A preload application step of applying a preload along the axial direction to the pair of rolling bearings;
In the preload application step,
A preloading jig arranging step of arranging a preloading jig capable of abutting one end face of the inner ring of the first rolling bearing on the one side of the shaft;
A pressing step of relatively pressing the inner rings of the pair of rolling bearings along the axial direction while bringing the one end surface of the inner ring of the first rolling bearing into contact with the preload jig;
A method for manufacturing a bearing device, comprising: It is a manufacturing method of the bearing device according to claim 2,
An adhesive application step of applying an adhesive for fixing the inner rings of the pair of rolling bearings to the outer peripheral surface of the shaft;
In the adhesive application step, the adhesive is applied to the region on the other side of the flange while applying the adhesive to the region on the one side of the flange on the outer peripheral surface of the shaft. A method for manufacturing a bearing device. A bearing device according to claim 1;
A housing that supports one end of the bearing device;
A rotating member that is fitted around the pair of rolling bearings and rotates about the axis of the shaft;
A slider mounted on the rotating member for recording and reproducing information with a magnetic recording medium;
With
The information recording / reproducing apparatus is characterized in that the bearing device is supported by the housing in a state in which the bottom of the housing is in contact with one end surface of the inner ring of the first rolling bearing. The bearing device according to claim 9,
A cover member for covering the opening of the housing and supporting the other end of the bearing device;
The information recording / reproducing apparatus, wherein the bearing device is supported by the cover member in a state where the cover member and the other end surface of the shaft are in contact with each other. The bearing device according to claim 9,
A cover member for covering the opening of the housing and supporting the other end of the bearing device;
The bearing device is supported by the cover member in a state in which the cover member is in contact with the other end surface of the inner ring of the second rolling bearing disposed on the other side in the axial direction. Information recording / reproducing apparatus.

Images